6x6 Chess Free Choice

I know there are many fans of this chess variant. This post is primarily for them.
Mini-chess can be a really interesting and addictive game, despite the small size of the board and the seeming lack of positional play and combinations.

Magnus Carlsen promoting 5×6 chess variant Chess Attack, by Wernerkling - Own work (https://commons.wikimedia.org/wiki/File:Magnus_k%C3%B8.jpg#/media/File:Magnus_kø.jpg)

There are many initial setups for a 6x6 board, and as a rule, one setup is pleasant to some but not to others.
For example, in Los Alamos Chess there are no bishops, in Diana Chess there is no queen.
There is Simpler Chess without rooks, knights, and even king and queen.

Los Alamos Chess, the first chess-like game played by a computer program.

It makes no sense to come up with any new setups for a 6x6 board - there will always be both supporters and opponents.
That is why the simplest and most optimal solution would be to allow the player to decide what initial setup he/she wants to play using a standard set of chess pieces.
The game begins with the fact that there are no chess pieces on the board apart from pawns on the second (white) and fifth (black) ranks.

6x6 Chess FC (Free Choice)

The players, each in turn, place any chess pieces on their last rank, except pawns. The game is impossible without the king, so the king must be placed on the board. When is the best time to do this, the player decides for himself/herself in any of the six turns.

Bishops can be placed on a square of the same color.

There is no pawn double-step move, nor is there en passant capture.

Pawns may promote to any chess pieces except king and pawn.

There is no castling.

Here's an example of 6x6 Chess FC:

Setup: 1. Ba1 Nc6 2. Rf1 Ne6 3. Nb1 Ra6 4. Ne1 Rb6 5. Qc1 Qd6 6. Kd1 Kf6

The Play: 1. d3 d4 2. e3 de 3. fe b4 4. Nd2 Qd5 5. Nc4 Rb5 6. e4 Qd4 7. Rxf5#